The complex interweaving of processes controlling the phosphate metabolism (Pi regulon) of the cells is studied in E. coli. Alkaline Phosphatase is one element of this regulon in which we focus our project. The immediate objectives are: a) to establish the number of genes involved in the Pi regulon and among them those genes regulating AP; b) to produce enough of the control gene products to allow biochemical studies and ultimately to understand their function; c) to study the transport of AP subunits across the cell membrane by using vesicles in an in vitro system; d) to further study the function of the Pi transport (PST) and accumulation of polyphosphates; and e) to study small, unidentified factors known to be effective in AP control.